Balancing on the Tides

Using a system of pivoting, barge-mounted towers, a Virginia contractor floated bridge segments into position 120 ft above the York River, reducing costs and cutting erection time by nearly two-thirds. Though still serviceable, the 44-year-old George P. Coleman Bridge at Yorktown, Va., was functionally obsolete by the late 1980s, carrying 25,000 vehicles daily over the York River on two lanes designed to accommodate 15,000. In 1989 the Virginia Department of Transportation (VDOT) asked the bridge's original designer, Parsons Brinckerhoff Quade & Douglas, New York, to prepare plans for widening the bridge from 31 ft to 77 ft, 4 in., while preserving its original swing-span drawbridge design.